Method for manufacturing a mold

ABSTRACT

The present invention relates to a method for manufacturing a mode for a light guide plate. The method includes the following steps: providing an organic substrate ( 30 ) having a main body ( 31 ) and a pattern ( 33 ) formed on a surface thereof; depositing a Ni film ( 32 ) on the pattern; forming a Ni layer ( 44 ) on the Ni film by an electroless plating method; removing the organic substrate thereby obtaining a Ni mold preform ( 60 ) with a pattern being formed thereon; attaching the Ni mold preform to a mold substrate ( 70 ) and obtaining a mold the light guide plate ( 80 ). The present invention has the advantages of simple processes and cost effectiveness.

FIELD OF THE INVENTION

The invention relates generally to a method for manufacturing a mold, more particularly, to a method for manufacturing a mold for forming a light guide plate with a pattern thereon.

DESCRIPTION OF RELATED ART

Liquid crystal display devices have been widely used in notebook computers or portable TVs. A liquid crystal display device generally comprises a liquid crystal panel and a backlight system. The backlight system is for providing uniform collimated light to the liquid crystal panel. The backlight system mainly comprises a light source and a light guide plate. The light guide plate is for guiding light beams emitted from the light source to uniformly illuminate the liquid crystal panel. Usually, a pattern is formed on the light guide plate for improving the uniformity of illuminance.

Method for forming a pattern on a light guide plate includes a printing method and a molding method. However, it is difficult for the printing method to control the quality of the optical pattern. Thus the molding method is becoming more and more popular. In the case of the molding method, an optical pattern is first formed on a mold. The optical pattern is then transferred on the light guide plate by an injection molding method or a direct impression method.

FIG. 7 shows a flow chart of a conventional method for manufacturing a mold with a pattern thereon. The method comprises the following steps: step 701: providing a substrate (i.e a mold preform) with a photo resistant layer thereon; step 702: forming a pattern in the photo resistant layer by a photolithography process; step 703: dry etching the substrate; and step704: removing remained photo resistant layer from the substrate. However, the step of dry etching 703 is complicated and has a high cost.

What is needed, therefore, is a method for manufacturing a mold for forming a light guide plate with a pattern thereon. The method is simple and cost-effective.

SUMMARY OF INVENTION

The present invention provides a method for manufacturing a mold. In one embodiment, the method comprises the following steps: providing an organic substrate has a main body and a pattern formed on a surface thereof, depositing a Ni film on the pattern of the substrate; forming a Ni layer on the Ni film by an electroless plating method; removing the organic substrate thereby obtaining a Ni mold preform with a pattern being formed thereon; and attaching the Ni mold preform to a mold substrate thereby obtaining a mold having the pattern thereon.

Compared with the conventional method for manufacturing a mold, the present method obviates the need of performing the step of etching and exposure. Therefore, the present method is simple and cost-effective.

Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

Many aspects of the present method can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, the emphasis instead being placed upon clearly illustrating the principles of the present method.

FIG. 1 is a flowchart of a method for manufacturing a mold in accordance with a preferred embodiment;

FIG. 2 is a schematic view showing a substrate having a pattern thereon in accordance with the preferred embodiment;

FIG. 3 is similar to FIG. 2, but showing a Ni film is deposited on the substrate of FIG. 2;

FIG. 4 is similar to FIG. 3, but showing a Ni layer is formed on the Ni film of the substrate of FIG. 3;

FIG. 5 is a schematic view showing a Ni mold preform;

FIG. 6 is a schematic view showing a mold having a pattern; and

FIG. 7 is a flowchart of a conventional method for manufacturing a mold.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one preferred embodiment of the present invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

Reference will now be made to the drawings to describe embodiments of the present invention, in detail.

Referring to FIG. 1 shows a method for making a mold, according to an exemplary embodiment. The method comprises the steps of: step 101: preparing an organic substrate having a main body and a pattern formed on a surface thereof; step 102: depositing a Ni film on the pattern of the substrate; step 103: forming a Ni layer on the Ni film by an electroless plating method (also referred to as a chemical plating method, or an auto-catalytic plating method); step 104: dissolving/removing the organic substrate using an organic solvent thereby obtaining a Ni mold preform with a corresponding pattern formed thereon; and step 105: attaching the Ni mold preform to a mold substrate thereby obtaining a mold having the pattern thereon.

FIG. 2 shows the organic substrate 30 having the body 31 and the patterned 33. The material of the organic substrate 30 may be polymethylmethacrylate or polyester carbonate. The organic substrate 30 is formed by an injection molding process. The pattern 33 is defined by a photolithography method. The pattern 33 may include a plurality of semi-spheres or cylinders.

Referring to FIG. 3, the Ni film 32 may be deposited on the substrate by a chemical vapor deposition or a sputtering deposition method. In the illustrated embodiment, the Ni film 32 is formed by plasma sputtering deposition method. The substrate 30 is initially placed in a plasma sputtering apparatus (not shown). The working pressure of the plasma sputtering apparatus is configured to be about 0.05 torr. The working temperature of the plasma sputtering apparatus is configured to be about 150° C. Reactant gases are then introduced in a reaction chamber of the plasma sputtering apparatus so as to form plasma. The Ni film with a thickness of 200˜500 Å is then formed on the pattern of the substrate 30. The treated substrate having the Ni film 32 thereon is identified with reference numeral 40.

FIG. 4 shows the Ni layer 44 is formed on the Ni film 40 of the substrate. The Ni layer 44 is formed in a plating solution by the electroless plating method. The plating solution contains metal ions, and a reducing agent. A catalyst is utilized to catalyze the redox reaction, thereby the metal ions being reduced from its ionic state into solid metal state. The reducing agent is generally sodium borohydride or hypophosphite. The plating solution is an acid solution with a PH value in the range from about 4.2 to about 4.8. The plating solution may be an alkaline solution. The thickness of the Ni layer 44 may be configured by controlling the time period of the electroless plating process. As a result, the Ni layer 44 is formed on the Ni film surface of the treated substrate 40 thereby obtaining a semi-product having the treated substrate 50 with the Ni film 32 and the Ni layer 44 thereon. The semi-product is identified with reference number 50.

In step 104, the substrate 50 is dissolved/removed in an organic solvent. The organic solvent generally contains acetone. Referring to FIG. 6, due to the organic substrate 30 being dissolved in the organic solvent, the resultant product is a Ni mold preform 60. The Ni mold perform 60 is essentially a combination of the Ni film 32 and the Ni layer 44.

FIG. 7 shows a mold 80. The mold 80 is essentially a combination of the Ni mold preform 60 and a mold substrate 70. The mold 80 may be made by a hot pressing method at an appropriate working temperature.

The present process does not include the steps of etching and exposure of the conventional method for making a mold. Therefore, comparing with the conventional method, the present method is simple and cost-effective.

Finally, it is to be understood that the above-described embodiments are intended to illustrate rather than limit the invention. Variations may be made to the embodiments without departing from the spirit of the invention as claimed. The above-described embodiments illustrate the scope of the invention but do not restrict the scope of the invention. 

1. A method for manufacturing a mold comprising: providing an organic substrate having a main body and a pattern provided on the main body; depositing a Ni film on the pattern of the organic substrate; forming a Ni layer on the Ni film by an electroless plating method; removing the organic substrate thereby obtaining a Ni mold preform with a pattern being formed thereon; and attaching the Ni mold preform to a mold substrate thereby obtaining a mold having the pattern thereon.
 2. The method as claimed in claim 1, wherein the material of the organic substrate is comprised of polymethylmethacrylate.
 3. The method as claimed in claim 1, wherein the material of the organic substrate is polyester carbonate.
 4. The method as claimed in claim 1, wherein the pattern of the organic substrate is formed by a photolithography method.
 5. The method as claimed in claim 1, wherein the main body and the pattern of the organic substrate are integrally formed by an injection molding process.
 6. The method as claimed in claim 1, wherein the pattern comprises a plurality of semi-spheres.
 7. The method as claimed in claim 1, wherein the pattern comprises a plurality of cylinders.
 8. The method as claimed in claim 1, wherein the Ni film is formed by a chemical vapor deposition method.
 9. The method as claimed in claim 1, wherein the Ni film is formed by a sputtering deposition method.
 10. The method as claimed in claim 1, wherein during performing the electroless plating method, an acid solution is employed as a plating solution.
 11. The method as claimed in claim 11, wherein the PH value of the acid solution is in the range from about 4.2 to about 4.8.
 12. The method as claimed in claim 1, wherein during performing the electroless plating method, an alkaline solution is employed as a plating solution.
 13. The method as claimed in claim 1, wherein the organic solvent contains acetone.
 14. The method as claimed in claim 1, wherein the Ni mold preform and the mold substrate are combined by a hot pressing method. 